Al-Aqsa Martyrs Brigades members Fahd Bin Hodi and Uthman Yunis, aged 25 and 27 respectively, were captured on Tuesday from Rafadiya Hospital in Nablus where they had been admitted last Friday.
The two were being treated for serious wounds after Israeli troops shot at them on the roof top of a hospital.
"You cannot just arrest a patient in intensive care. His life is in danger now," said one hospital official.
Khalid Namrudi, the local leader of the group which is the armed faction of Palestinian President Yasir Arafat’s Fatah group, was shot dead by Israeli troops after the three were seen on the hospital’s roof.
The Israeli soldiers had surrounded the hospital on Tuesday before storming the hospital to capture the two casualties and evacuating them in ambulances.
Israeli public radio said the two had been transferred to Belinsohn Hospital in Tel Aviv, and would be questioned by agents from the domestic intelligence service, Shin Beth, over their involvement in resistance activities.
Yunis has helped organise resistance operations, said an Al-Aqsa spokesperson.
All Hamas activists 'legitimate'
targets for Israeli soldiers
In the last week Israel has stepped up attacks against Palestinian resistance fighters. Israel’s Chief of Staff Lieutenant General Moshe Yaalon has made clear that all members of Hamas are targets for "liquidation."
Palestinians and the international community condemn Israel’s policy of targeted killings.
Hamas leaflets hung in mosques throughout the Gaza Strip, instructing members to take precautions - such as not travelling in groups, avoiding use of their telephones, using makeup to disguise themselves and staying off main streets -so as not to be easy targets for Israeli assassination.
Arafat has been under intense US and Israeli pressure to dismantle resistance groups.
But top Hamas leader Khalid Mashaal said it was unlikely Arafat would bow to US pressure, saying the veteran Palestinian leader had previous experience with Washington.
"Even if Arafat agreed to crackdown on factions, Israel and the United States would not be satisfied," he said in an exclusive interview with Aljazeera.
Last week the Palestinian Authority ordered all Hamas leaders to end interviews with media, following a blast on a west Jerusalem bus, carried out by a Hamas activist.
In related developments, Palestinian Prime Minister, Mahmud Abbas, may hold talks with Hamas and Islamic Jihad to discuss restoring a truce aimed at temporarily halting anti-occupation attacks, Palestinian sources told our correspondent.
Abbas had cut off ties with the two groups, following the bus blast.
Meanwhile, Israeli tanks launched an incursion into the occupied West Bank city of Jenin, injuring at least one Palestinian.
Israel imposed a curfew on the city and stormed homes.
Another three Palestinian civilians were injured when Israeli tanks attacked an area in the southern occupied Gaza Strip.